drivers/thermal/thermal_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  thermal.c - Generic Thermal Management Sysfs support.
   4  *
   5  *  Copyright (C) 2008 Intel Corp
   6  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
   7  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/device.h>
  13 #include <linux/err.h>
  14 #include <linux/export.h>
  15 #include <linux/slab.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/idr.h>
  18 #include <linux/thermal.h>
  19 #include <linux/reboot.h>
  20 #include <linux/string.h>
  21 #include <linux/of.h>
  22 #include <linux/suspend.h>
  23
  24 #define CREATE_TRACE_POINTS
  25 #include <trace/events/thermal.h>
  26
  27 #include "thermal_core.h"
  28 #include "thermal_hwmon.h"
  29
  30 static DEFINE_IDA(thermal_tz_ida);
  31 static DEFINE_IDA(thermal_cdev_ida);
  32
  33 static LIST_HEAD(thermal_tz_list);
  34 static LIST_HEAD(thermal_cdev_list);
  35 static LIST_HEAD(thermal_governor_list);
  36
  37 static DEFINE_MUTEX(thermal_list_lock);
  38 static DEFINE_MUTEX(thermal_governor_lock);
  39 static DEFINE_MUTEX(poweroff_lock);
  40
  41 static atomic_t in_suspend;
  42 static bool power_off_triggered;
  43
  44 static struct thermal_governor *def_governor;
  45
  46 /*
  47  * Governor section: set of functions to handle thermal governors
  48  *
  49  * Functions to help in the life cycle of thermal governors within
  50  * the thermal core and by the thermal governor code.
  51  */
  52
  53 static struct thermal_governor *__find_governor(const char *name)
  54 {
  55         struct thermal_governor *pos;
  56
  57         if (!name || !name[0])
  58                 return def_governor;
  59
  60         list_for_each_entry(pos, &thermal_governor_list, governor_list)
  61                 if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  62                         return pos;
  63
  64         return NULL;
  65 }
  66
  67 /**
  68  * bind_previous_governor() - bind the previous governor of the thermal zone
  69  * @tz:         a valid pointer to a struct thermal_zone_device
  70  * @failed_gov_name:    the name of the governor that failed to register
  71  *
  72  * Register the previous governor of the thermal zone after a new
  73  * governor has failed to be bound.
  74  */
  75 static void bind_previous_governor(struct thermal_zone_device *tz,
  76                                    const char *failed_gov_name)
  77 {
  78         if (tz->governor && tz->governor->bind_to_tz) {
  79                 if (tz->governor->bind_to_tz(tz)) {
  80                         dev_err(&tz->device,
  81                                 "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  82                                 failed_gov_name, tz->governor->name, tz->type);
  83                         tz->governor = NULL;
  84                 }
  85         }
  86 }
  87
  88 /**
  89  * thermal_set_governor() - Switch to another governor
  90  * @tz:         a valid pointer to a struct thermal_zone_device
  91  * @new_gov:    pointer to the new governor
  92  *
  93  * Change the governor of thermal zone @tz.
  94  *
  95  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  96  */
  97 static int thermal_set_governor(struct thermal_zone_device *tz,
  98                                 struct thermal_governor *new_gov)
  99 {
 100         int ret = 0;
 101
 102         if (tz->governor && tz->governor->unbind_from_tz)
 103                 tz->governor->unbind_from_tz(tz);
 104
 105         if (new_gov && new_gov->bind_to_tz) {
 106                 ret = new_gov->bind_to_tz(tz);
 107                 if (ret) {
 108                         bind_previous_governor(tz, new_gov->name);
 109
 110                         return ret;
 111                 }
 112         }
 113
 114         tz->governor = new_gov;
 115
 116         return ret;
 117 }
 118
 119 int thermal_register_governor(struct thermal_governor *governor)
 120 {
 121         int err;
 122         const char *name;
 123         struct thermal_zone_device *pos;
 124
 125         if (!governor)
 126                 return -EINVAL;
 127
 128         mutex_lock(&thermal_governor_lock);
 129
 130         err = -EBUSY;
 131         if (!__find_governor(governor->name)) {
 132                 bool match_default;
 133
 134                 err = 0;
 135                 list_add(&governor->governor_list, &thermal_governor_list);
 136                 match_default = !strncmp(governor->name,
 137                                          DEFAULT_THERMAL_GOVERNOR,
 138                                          THERMAL_NAME_LENGTH);
 139
 140                 if (!def_governor && match_default)
 141                         def_governor = governor;
 142         }
 143
 144         mutex_lock(&thermal_list_lock);
 145
 146         list_for_each_entry(pos, &thermal_tz_list, node) {
 147                 /*
 148                  * only thermal zones with specified tz->tzp->governor_name
 149                  * may run with tz->govenor unset
 150                  */
 151                 if (pos->governor)
 152                         continue;
 153
 154                 name = pos->tzp->governor_name;
 155
 156                 if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 157                         int ret;
 158
 159                         ret = thermal_set_governor(pos, governor);
 160                         if (ret)
 161                                 dev_err(&pos->device,
 162                                         "Failed to set governor %s for thermal zone %s: %d\n",
 163                                         governor->name, pos->type, ret);
 164                 }
 165         }
 166
 167         mutex_unlock(&thermal_list_lock);
 168         mutex_unlock(&thermal_governor_lock);
 169
 170         return err;
 171 }
 172
 173 void thermal_unregister_governor(struct thermal_governor *governor)
 174 {
 175         struct thermal_zone_device *pos;
 176
 177         if (!governor)
 178                 return;
 179
 180         mutex_lock(&thermal_governor_lock);
 181
 182         if (!__find_governor(governor->name))
 183                 goto exit;
 184
 185         mutex_lock(&thermal_list_lock);
 186
 187         list_for_each_entry(pos, &thermal_tz_list, node) {
 188                 if (!strncasecmp(pos->governor->name, governor->name,
 189                                  THERMAL_NAME_LENGTH))
 190                         thermal_set_governor(pos, NULL);
 191         }
 192
 193         mutex_unlock(&thermal_list_lock);
 194         list_del(&governor->governor_list);
 195 exit:
 196         mutex_unlock(&thermal_governor_lock);
 197 }
 198
 199 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 200                                    char *policy)
 201 {
 202         struct thermal_governor *gov;
 203         int ret = -EINVAL;
 204
 205         mutex_lock(&thermal_governor_lock);
 206         mutex_lock(&tz->lock);
 207
 208         gov = __find_governor(strim(policy));
 209         if (!gov)
 210                 goto exit;
 211
 212         ret = thermal_set_governor(tz, gov);
 213
 214 exit:
 215         mutex_unlock(&tz->lock);
 216         mutex_unlock(&thermal_governor_lock);
 217
 218         thermal_notify_tz_gov_change(tz->id, policy);
 219
 220         return ret;
 221 }
 222
 223 int thermal_build_list_of_policies(char *buf)
 224 {
 225         struct thermal_governor *pos;
 226         ssize_t count = 0;
 227         ssize_t size = PAGE_SIZE;
 228
 229         mutex_lock(&thermal_governor_lock);
 230
 231         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 232                 size = PAGE_SIZE - count;
 233                 count += scnprintf(buf + count, size, "%s ", pos->name);
 234         }
 235         count += scnprintf(buf + count, size, "\n");
 236
 237         mutex_unlock(&thermal_governor_lock);
 238
 239         return count;
 240 }
 241
 242 static void __init thermal_unregister_governors(void)
 243 {
 244         struct thermal_governor **governor;
 245
 246         for_each_governor_table(governor)
 247                 thermal_unregister_governor(*governor);
 248 }
 249
 250 static int __init thermal_register_governors(void)
 251 {
 252         int ret = 0;
 253         struct thermal_governor **governor;
 254
 255         for_each_governor_table(governor) {
 256                 ret = thermal_register_governor(*governor);
 257                 if (ret) {
 258                         pr_err("Failed to register governor: '%s'",
 259                                (*governor)->name);
 260                         break;
 261                 }
 262
 263                 pr_info("Registered thermal governor '%s'",
 264                         (*governor)->name);
 265         }
 266
 267         if (ret) {
 268                 struct thermal_governor **gov;
 269
 270                 for_each_governor_table(gov) {
 271                         if (gov == governor)
 272                                 break;
 273                         thermal_unregister_governor(*gov);
 274                 }
 275         }
 276
 277         return ret;
 278 }
 279
 280 /*
 281  * Zone update section: main control loop applied to each zone while monitoring
 282  *
 283  * in polling mode. The monitoring is done using a workqueue.
 284  * Same update may be done on a zone by calling thermal_zone_device_update().
 285  *
 286  * An update means:
 287  * - Non-critical trips will invoke the governor responsible for that zone;
 288  * - Hot trips will produce a notification to userspace;
 289  * - Critical trip point will cause a system shutdown.
 290  */
 291 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 292                                             int delay)
 293 {
 294         if (delay > 1000)
 295                 mod_delayed_work(system_freezable_power_efficient_wq,
 296                                  &tz->poll_queue,
 297                                  round_jiffies(msecs_to_jiffies(delay)));
 298         else if (delay)
 299                 mod_delayed_work(system_freezable_power_efficient_wq,
 300                                  &tz->poll_queue,
 301                                  msecs_to_jiffies(delay));
 302         else
 303                 cancel_delayed_work(&tz->poll_queue);
 304 }
 305
 306 static inline bool should_stop_polling(struct thermal_zone_device *tz)
 307 {
 308         return !thermal_zone_device_is_enabled(tz);
 309 }
 310
 311 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 312 {
 313         bool stop;
 314
 315         stop = should_stop_polling(tz);
 316
 317         mutex_lock(&tz->lock);
 318
 319         if (!stop && tz->passive)
 320                 thermal_zone_device_set_polling(tz, tz->passive_delay);
 321         else if (!stop && tz->polling_delay)
 322                 thermal_zone_device_set_polling(tz, tz->polling_delay);
 323         else
 324                 thermal_zone_device_set_polling(tz, 0);
 325
 326         mutex_unlock(&tz->lock);
 327 }
 328
 329 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 330 {
 331         tz->governor ? tz->governor->throttle(tz, trip) :
 332                        def_governor->throttle(tz, trip);
 333 }
 334
 335 /**
 336  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 337  * @work: work_struct associated with the emergency poweroff function
 338  *
 339  * This function is called in very critical situations to force
 340  * a kernel poweroff after a configurable timeout value.
 341  */
 342 static void thermal_emergency_poweroff_func(struct work_struct *work)
 343 {
 344         /*
 345          * We have reached here after the emergency thermal shutdown
 346          * Waiting period has expired. This means orderly_poweroff has
 347          * not been able to shut off the system for some reason.
 348          * Try to shut down the system immediately using kernel_power_off
 349          * if populated
 350          */
 351         WARN(1, "Attempting kernel_power_off: Temperature too high\n");
 352         kernel_power_off();
 353
 354         /*
 355          * Worst of the worst case trigger emergency restart
 356          */
 357         WARN(1, "Attempting emergency_restart: Temperature too high\n");
 358         emergency_restart();
 359 }
 360
 361 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
 362                             thermal_emergency_poweroff_func);
 363
 364 /**
 365  * thermal_emergency_poweroff - Trigger an emergency system poweroff
 366  *
 367  * This may be called from any critical situation to trigger a system shutdown
 368  * after a known period of time. By default this is not scheduled.
 369  */
 370 static void thermal_emergency_poweroff(void)
 371 {
 372         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 373         /*
 374          * poweroff_delay_ms must be a carefully profiled positive value.
 375          * Its a must for thermal_emergency_poweroff_work to be scheduled
 376          */
 377         if (poweroff_delay_ms <= 0)
 378                 return;
 379         schedule_delayed_work(&thermal_emergency_poweroff_work,
 380                               msecs_to_jiffies(poweroff_delay_ms));
 381 }
 382
 383 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 384 {
 385         dev_emerg(&tz->device, "%s: critical temperature reached, "
 386                   "shutting down\n", tz->type);
 387
 388         mutex_lock(&poweroff_lock);
 389         if (!power_off_triggered) {
 390                 /*
 391                  * Queue a backup emergency shutdown in the event of
 392                  * orderly_poweroff failure
 393                  */
 394                 thermal_emergency_poweroff();
 395                 orderly_poweroff(true);
 396                 power_off_triggered = true;
 397         }
 398         mutex_unlock(&poweroff_lock);
 399 }
 400 EXPORT_SYMBOL(thermal_zone_device_critical);
 401
 402 static void handle_critical_trips(struct thermal_zone_device *tz,
 403                                   int trip, enum thermal_trip_type trip_type)
 404 {
 405         int trip_temp;
 406
 407         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 408
 409         /* If we have not crossed the trip_temp, we do not care. */
 410         if (trip_temp <= 0 || tz->temperature < trip_temp)
 411                 return;
 412
 413         trace_thermal_zone_trip(tz, trip, trip_type);
 414
 415         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
 416                 tz->ops->hot(tz);
 417         else if (trip_type == THERMAL_TRIP_CRITICAL)
 418                 tz->ops->critical(tz);
 419 }
 420
 421 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 422 {
 423         enum thermal_trip_type type;
 424         int trip_temp, hyst = 0;
 425
 426         /* Ignore disabled trip points */
 427         if (test_bit(trip, &tz->trips_disabled))
 428                 return;
 429
 430         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 431         tz->ops->get_trip_type(tz, trip, &type);
 432         if (tz->ops->get_trip_hyst)
 433                 tz->ops->get_trip_hyst(tz, trip, &hyst);
 434
 435         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 436                 if (tz->last_temperature < trip_temp &&
 437                     tz->temperature >= trip_temp)
 438                         thermal_notify_tz_trip_up(tz->id, trip);
 439                 if (tz->last_temperature >= trip_temp &&
 440                     tz->temperature < (trip_temp - hyst))
 441                         thermal_notify_tz_trip_down(tz->id, trip);
 442         }
 443
 444         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
 445                 handle_critical_trips(tz, trip, type);
 446         else
 447                 handle_non_critical_trips(tz, trip);
 448         /*
 449          * Alright, we handled this trip successfully.
 450          * So, start monitoring again.
 451          */
 452         monitor_thermal_zone(tz);
 453 }
 454
 455 static void update_temperature(struct thermal_zone_device *tz)
 456 {
 457         int temp, ret;
 458
 459         ret = thermal_zone_get_temp(tz, &temp);
 460         if (ret) {
 461                 if (ret != -EAGAIN)
 462                         dev_warn(&tz->device,
 463                                  "failed to read out thermal zone (%d)\n",
 464                                  ret);
 465                 return;
 466         }
 467
 468         mutex_lock(&tz->lock);
 469         tz->last_temperature = tz->temperature;
 470         tz->temperature = temp;
 471         mutex_unlock(&tz->lock);
 472
 473         trace_thermal_temperature(tz);
 474
 475         thermal_genl_sampling_temp(tz->id, temp);
 476 }
 477
 478 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 479 {
 480         struct thermal_instance *pos;
 481         tz->temperature = THERMAL_TEMP_INVALID;
 482         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 483                 pos->initialized = false;
 484 }
 485
 486 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
 487 {
 488         tz->passive = 0;
 489         thermal_zone_device_init(tz);
 490 }
 491
 492 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 493                                         enum thermal_device_mode mode)
 494 {
 495         int ret = 0;
 496
 497         mutex_lock(&tz->lock);
 498
 499         /* do nothing if mode isn't changing */
 500         if (mode == tz->mode) {
 501                 mutex_unlock(&tz->lock);
 502
 503                 return ret;
 504         }
 505
 506         if (tz->ops->change_mode)
 507                 ret = tz->ops->change_mode(tz, mode);
 508
 509         if (!ret)
 510                 tz->mode = mode;
 511
 512         mutex_unlock(&tz->lock);
 513
 514         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 515
 516         if (mode == THERMAL_DEVICE_ENABLED)
 517                 thermal_notify_tz_enable(tz->id);
 518         else
 519                 thermal_notify_tz_disable(tz->id);
 520
 521         return ret;
 522 }
 523
 524 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 525 {
 526         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 527 }
 528 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 529
 530 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 531 {
 532         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 533 }
 534 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 535
 536 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 537 {
 538         enum thermal_device_mode mode;
 539
 540         mutex_lock(&tz->lock);
 541
 542         mode = tz->mode;
 543
 544         mutex_unlock(&tz->lock);
 545
 546         return mode == THERMAL_DEVICE_ENABLED;
 547 }
 548
 549 void thermal_zone_device_update(struct thermal_zone_device *tz,
 550                                 enum thermal_notify_event event)
 551 {
 552         int count;
 553
 554         if (should_stop_polling(tz))
 555                 return;
 556
 557         if (atomic_read(&in_suspend))
 558                 return;
 559
 560         if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
 561                       "'get_temp' ops set\n", __func__))
 562                 return;
 563
 564         update_temperature(tz);
 565
 566         thermal_zone_set_trips(tz);
 567
 568         tz->notify_event = event;
 569
 570         for (count = 0; count < tz->trips; count++)
 571                 handle_thermal_trip(tz, count);
 572 }
 573 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 574
 575 /**
 576  * thermal_notify_framework - Sensor drivers use this API to notify framework
 577  * @tz:         thermal zone device
 578  * @trip:       indicates which trip point has been crossed
 579  *
 580  * This function handles the trip events from sensor drivers. It starts
 581  * throttling the cooling devices according to the policy configured.
 582  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 583  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 584  * The throttling policy is based on the configured platform data; if no
 585  * platform data is provided, this uses the step_wise throttling policy.
 586  */
 587 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 588 {
 589         handle_thermal_trip(tz, trip);
 590 }
 591 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 592
 593 static void thermal_zone_device_check(struct work_struct *work)
 594 {
 595         struct thermal_zone_device *tz = container_of(work, struct
 596                                                       thermal_zone_device,
 597                                                       poll_queue.work);
 598         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 599 }
 600
 601 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
 602                                           const char *cdev_type, size_t size)
 603 {
 604         struct thermal_cooling_device *cdev = NULL;
 605
 606         mutex_lock(&thermal_list_lock);
 607         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 608                 /* skip non matching cdevs */
 609                 if (strncmp(cdev_type, cdev->type, size))
 610                         continue;
 611
 612                 /* re binding the exception matching the type pattern */
 613                 thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
 614                                                  THERMAL_NO_LIMIT,
 615                                                  THERMAL_NO_LIMIT,
 616                                                  THERMAL_WEIGHT_DEFAULT);
 617         }
 618         mutex_unlock(&thermal_list_lock);
 619 }
 620
 621 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 622                               void *data)
 623 {
 624         struct thermal_governor *gov;
 625         int ret = 0;
 626
 627         mutex_lock(&thermal_governor_lock);
 628         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 629                 ret = cb(gov, data);
 630                 if (ret)
 631                         break;
 632         }
 633         mutex_unlock(&thermal_governor_lock);
 634
 635         return ret;
 636 }
 637
 638 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 639                                               void *), void *data)
 640 {
 641         struct thermal_cooling_device *cdev;
 642         int ret = 0;
 643
 644         mutex_lock(&thermal_list_lock);
 645         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 646                 ret = cb(cdev, data);
 647                 if (ret)
 648                         break;
 649         }
 650         mutex_unlock(&thermal_list_lock);
 651
 652         return ret;
 653 }
 654
 655 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 656                           void *data)
 657 {
 658         struct thermal_zone_device *tz;
 659         int ret = 0;
 660
 661         mutex_lock(&thermal_list_lock);
 662         list_for_each_entry(tz, &thermal_tz_list, node) {
 663                 ret = cb(tz, data);
 664                 if (ret)
 665                         break;
 666         }
 667         mutex_unlock(&thermal_list_lock);
 668
 669         return ret;
 670 }
 671
 672 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 673 {
 674         struct thermal_zone_device *tz, *match = NULL;
 675
 676         mutex_lock(&thermal_list_lock);
 677         list_for_each_entry(tz, &thermal_tz_list, node) {
 678                 if (tz->id == id) {
 679                         match = tz;
 680                         break;
 681                 }
 682         }
 683         mutex_unlock(&thermal_list_lock);
 684
 685         return match;
 686 }
 687
 688 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
 689                                           const char *cdev_type, size_t size)
 690 {
 691         struct thermal_cooling_device *cdev = NULL;
 692
 693         mutex_lock(&thermal_list_lock);
 694         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 695                 /* skip non matching cdevs */
 696                 if (strncmp(cdev_type, cdev->type, size))
 697                         continue;
 698                 /* unbinding the exception matching the type pattern */
 699                 thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
 700                                                    cdev);
 701         }
 702         mutex_unlock(&thermal_list_lock);
 703 }
 704
 705 /*
 706  * Device management section: cooling devices, zones devices, and binding
 707  *
 708  * Set of functions provided by the thermal core for:
 709  * - cooling devices lifecycle: registration, unregistration,
 710  *                              binding, and unbinding.
 711  * - thermal zone devices lifecycle: registration, unregistration,
 712  *                                   binding, and unbinding.
 713  */
 714
 715 /**
 716  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 717  * @tz:         pointer to struct thermal_zone_device
 718  * @trip:       indicates which trip point the cooling devices is
 719  *              associated with in this thermal zone.
 720  * @cdev:       pointer to struct thermal_cooling_device
 721  * @upper:      the Maximum cooling state for this trip point.
 722  *              THERMAL_NO_LIMIT means no upper limit,
 723  *              and the cooling device can be in max_state.
 724  * @lower:      the Minimum cooling state can be used for this trip point.
 725  *              THERMAL_NO_LIMIT means no lower limit,
 726  *              and the cooling device can be in cooling state 0.
 727  * @weight:     The weight of the cooling device to be bound to the
 728  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 729  *              default value
 730  *
 731  * This interface function bind a thermal cooling device to the certain trip
 732  * point of a thermal zone device.
 733  * This function is usually called in the thermal zone device .bind callback.
 734  *
 735  * Return: 0 on success, the proper error value otherwise.
 736  */
 737 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 738                                      int trip,
 739                                      struct thermal_cooling_device *cdev,
 740                                      unsigned long upper, unsigned long lower,
 741                                      unsigned int weight)
 742 {
 743         struct thermal_instance *dev;
 744         struct thermal_instance *pos;
 745         struct thermal_zone_device *pos1;
 746         struct thermal_cooling_device *pos2;
 747         unsigned long max_state;
 748         int result, ret;
 749
 750         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 751                 return -EINVAL;
 752
 753         list_for_each_entry(pos1, &thermal_tz_list, node) {
 754                 if (pos1 == tz)
 755                         break;
 756         }
 757         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 758                 if (pos2 == cdev)
 759                         break;
 760         }
 761
 762         if (tz != pos1 || cdev != pos2)
 763                 return -EINVAL;
 764
 765         ret = cdev->ops->get_max_state(cdev, &max_state);
 766         if (ret)
 767                 return ret;
 768
 769         /* lower default 0, upper default max_state */
 770         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 771         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 772
 773         if (lower > upper || upper > max_state)
 774                 return -EINVAL;
 775
 776         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 777         if (!dev)
 778                 return -ENOMEM;
 779         dev->tz = tz;
 780         dev->cdev = cdev;
 781         dev->trip = trip;
 782         dev->upper = upper;
 783         dev->lower = lower;
 784         dev->target = THERMAL_NO_TARGET;
 785         dev->weight = weight;
 786
 787         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 788         if (result < 0)
 789                 goto free_mem;
 790
 791         dev->id = result;
 792         sprintf(dev->name, "cdev%d", dev->id);
 793         result =
 794             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 795         if (result)
 796                 goto release_ida;
 797
 798         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 799         sysfs_attr_init(&dev->attr.attr);
 800         dev->attr.attr.name = dev->attr_name;
 801         dev->attr.attr.mode = 0444;
 802         dev->attr.show = trip_point_show;
 803         result = device_create_file(&tz->device, &dev->attr);
 804         if (result)
 805                 goto remove_symbol_link;
 806
 807         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 808         sysfs_attr_init(&dev->weight_attr.attr);
 809         dev->weight_attr.attr.name = dev->weight_attr_name;
 810         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 811         dev->weight_attr.show = weight_show;
 812         dev->weight_attr.store = weight_store;
 813         result = device_create_file(&tz->device, &dev->weight_attr);
 814         if (result)
 815                 goto remove_trip_file;
 816
 817         mutex_lock(&tz->lock);
 818         mutex_lock(&cdev->lock);
 819         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 820                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 821                         result = -EEXIST;
 822                         break;
 823                 }
 824         if (!result) {
 825                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 826                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 827                 atomic_set(&tz->need_update, 1);
 828         }
 829         mutex_unlock(&cdev->lock);
 830         mutex_unlock(&tz->lock);
 831
 832         if (!result)
 833                 return 0;
 834
 835         device_remove_file(&tz->device, &dev->weight_attr);
 836 remove_trip_file:
 837         device_remove_file(&tz->device, &dev->attr);
 838 remove_symbol_link:
 839         sysfs_remove_link(&tz->device.kobj, dev->name);
 840 release_ida:
 841         ida_simple_remove(&tz->ida, dev->id);
 842 free_mem:
 843         kfree(dev);
 844         return result;
 845 }
 846 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 847
 848 /**
 849  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 850  *                                        thermal zone.
 851  * @tz:         pointer to a struct thermal_zone_device.
 852  * @trip:       indicates which trip point the cooling devices is
 853  *              associated with in this thermal zone.
 854  * @cdev:       pointer to a struct thermal_cooling_device.
 855  *
 856  * This interface function unbind a thermal cooling device from the certain
 857  * trip point of a thermal zone device.
 858  * This function is usually called in the thermal zone device .unbind callback.
 859  *
 860  * Return: 0 on success, the proper error value otherwise.
 861  */
 862 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 863                                        int trip,
 864                                        struct thermal_cooling_device *cdev)
 865 {
 866         struct thermal_instance *pos, *next;
 867
 868         mutex_lock(&tz->lock);
 869         mutex_lock(&cdev->lock);
 870         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 871                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 872                         list_del(&pos->tz_node);
 873                         list_del(&pos->cdev_node);
 874                         mutex_unlock(&cdev->lock);
 875                         mutex_unlock(&tz->lock);
 876                         goto unbind;
 877                 }
 878         }
 879         mutex_unlock(&cdev->lock);
 880         mutex_unlock(&tz->lock);
 881
 882         return -ENODEV;
 883
 884 unbind:
 885         device_remove_file(&tz->device, &pos->weight_attr);
 886         device_remove_file(&tz->device, &pos->attr);
 887         sysfs_remove_link(&tz->device.kobj, pos->name);
 888         ida_simple_remove(&tz->ida, pos->id);
 889         kfree(pos);
 890         return 0;
 891 }
 892 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 893
 894 static void thermal_release(struct device *dev)
 895 {
 896         struct thermal_zone_device *tz;
 897         struct thermal_cooling_device *cdev;
 898
 899         if (!strncmp(dev_name(dev), "thermal_zone",
 900                      sizeof("thermal_zone") - 1)) {
 901                 tz = to_thermal_zone(dev);
 902                 thermal_zone_destroy_device_groups(tz);
 903                 kfree(tz);
 904         } else if (!strncmp(dev_name(dev), "cooling_device",
 905                             sizeof("cooling_device") - 1)) {
 906                 cdev = to_cooling_device(dev);
 907                 kfree(cdev);
 908         }
 909 }
 910
 911 static struct class thermal_class = {
 912         .name = "thermal",
 913         .dev_release = thermal_release,
 914 };
 915
 916 static inline
 917 void print_bind_err_msg(struct thermal_zone_device *tz,
 918                         struct thermal_cooling_device *cdev, int ret)
 919 {
 920         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 921                 tz->type, cdev->type, ret);
 922 }
 923
 924 static void __bind(struct thermal_zone_device *tz, int mask,
 925                    struct thermal_cooling_device *cdev,
 926                    unsigned long *limits,
 927                    unsigned int weight)
 928 {
 929         int i, ret;
 930
 931         for (i = 0; i < tz->trips; i++) {
 932                 if (mask & (1 << i)) {
 933                         unsigned long upper, lower;
 934
 935                         upper = THERMAL_NO_LIMIT;
 936                         lower = THERMAL_NO_LIMIT;
 937                         if (limits) {
 938                                 lower = limits[i * 2];
 939                                 upper = limits[i * 2 + 1];
 940                         }
 941                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
 942                                                                upper, lower,
 943                                                                weight);
 944                         if (ret)
 945                                 print_bind_err_msg(tz, cdev, ret);
 946                 }
 947         }
 948 }
 949
 950 static void bind_cdev(struct thermal_cooling_device *cdev)
 951 {
 952         int i, ret;
 953         const struct thermal_zone_params *tzp;
 954         struct thermal_zone_device *pos = NULL;
 955
 956         mutex_lock(&thermal_list_lock);
 957
 958         list_for_each_entry(pos, &thermal_tz_list, node) {
 959                 if (!pos->tzp && !pos->ops->bind)
 960                         continue;
 961
 962                 if (pos->ops->bind) {
 963                         ret = pos->ops->bind(pos, cdev);
 964                         if (ret)
 965                                 print_bind_err_msg(pos, cdev, ret);
 966                         continue;
 967                 }
 968
 969                 tzp = pos->tzp;
 970                 if (!tzp || !tzp->tbp)
 971                         continue;
 972
 973                 for (i = 0; i < tzp->num_tbps; i++) {
 974                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
 975                                 continue;
 976                         if (tzp->tbp[i].match(pos, cdev))
 977                                 continue;
 978                         tzp->tbp[i].cdev = cdev;
 979                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
 980                                tzp->tbp[i].binding_limits,
 981                                tzp->tbp[i].weight);
 982                 }
 983         }
 984
 985         mutex_unlock(&thermal_list_lock);
 986 }
 987
 988 /**
 989  * __thermal_cooling_device_register() - register a new thermal cooling device
 990  * @np:         a pointer to a device tree node.
 991  * @type:       the thermal cooling device type.
 992  * @devdata:    device private data.
 993  * @ops:                standard thermal cooling devices callbacks.
 994  *
 995  * This interface function adds a new thermal cooling device (fan/processor/...)
 996  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 997  * to all the thermal zone devices registered at the same time.
 998  * It also gives the opportunity to link the cooling device to a device tree
 999  * node, so that it can be bound to a thermal zone created out of device tree.
1000  *
1001  * Return: a pointer to the created struct thermal_cooling_device or an
1002  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1003  */
1004 static struct thermal_cooling_device *
1005 __thermal_cooling_device_register(struct device_node *np,
1006                                   const char *type, void *devdata,
1007                                   const struct thermal_cooling_device_ops *ops)
1008 {
1009         struct thermal_cooling_device *cdev;
1010         struct thermal_zone_device *pos = NULL;
1011         int result;
1012
1013         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
1014                 return ERR_PTR(-EINVAL);
1015
1016         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1017             !ops->set_cur_state)
1018                 return ERR_PTR(-EINVAL);
1019
1020         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1021         if (!cdev)
1022                 return ERR_PTR(-ENOMEM);
1023
1024         result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
1025         if (result < 0) {
1026                 kfree(cdev);
1027                 return ERR_PTR(result);
1028         }
1029
1030         cdev->id = result;
1031         strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
1032         mutex_init(&cdev->lock);
1033         INIT_LIST_HEAD(&cdev->thermal_instances);
1034         cdev->np = np;
1035         cdev->ops = ops;
1036         cdev->updated = false;
1037         cdev->device.class = &thermal_class;
1038         cdev->devdata = devdata;
1039         thermal_cooling_device_setup_sysfs(cdev);
1040         dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
1041         result = device_register(&cdev->device);
1042         if (result) {
1043                 ida_simple_remove(&thermal_cdev_ida, cdev->id);
1044                 put_device(&cdev->device);
1045                 return ERR_PTR(result);
1046         }
1047
1048         /* Add 'this' new cdev to the global cdev list */
1049         mutex_lock(&thermal_list_lock);
1050         list_add(&cdev->node, &thermal_cdev_list);
1051         mutex_unlock(&thermal_list_lock);
1052
1053         /* Update binding information for 'this' new cdev */
1054         bind_cdev(cdev);
1055
1056         mutex_lock(&thermal_list_lock);
1057         list_for_each_entry(pos, &thermal_tz_list, node)
1058                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1059                         thermal_zone_device_update(pos,
1060                                                    THERMAL_EVENT_UNSPECIFIED);
1061         mutex_unlock(&thermal_list_lock);
1062
1063         return cdev;
1064 }
1065
1066 /**
1067  * thermal_cooling_device_register() - register a new thermal cooling device
1068  * @type:       the thermal cooling device type.
1069  * @devdata:    device private data.
1070  * @ops:                standard thermal cooling devices callbacks.
1071  *
1072  * This interface function adds a new thermal cooling device (fan/processor/...)
1073  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1074  * to all the thermal zone devices registered at the same time.
1075  *
1076  * Return: a pointer to the created struct thermal_cooling_device or an
1077  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1078  */
1079 struct thermal_cooling_device *
1080 thermal_cooling_device_register(const char *type, void *devdata,
1081                                 const struct thermal_cooling_device_ops *ops)
1082 {
1083         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1084 }
1085 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1086
1087 /**
1088  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1089  * @np:         a pointer to a device tree node.
1090  * @type:       the thermal cooling device type.
1091  * @devdata:    device private data.
1092  * @ops:                standard thermal cooling devices callbacks.
1093  *
1094  * This function will register a cooling device with device tree node reference.
1095  * This interface function adds a new thermal cooling device (fan/processor/...)
1096  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1097  * to all the thermal zone devices registered at the same time.
1098  *
1099  * Return: a pointer to the created struct thermal_cooling_device or an
1100  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1101  */
1102 struct thermal_cooling_device *
1103 thermal_of_cooling_device_register(struct device_node *np,
1104                                    const char *type, void *devdata,
1105                                    const struct thermal_cooling_device_ops *ops)
1106 {
1107         return __thermal_cooling_device_register(np, type, devdata, ops);
1108 }
1109 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1110
1111 static void thermal_cooling_device_release(struct device *dev, void *res)
1112 {
1113         thermal_cooling_device_unregister(
1114                                 *(struct thermal_cooling_device **)res);
1115 }
1116
1117 /**
1118  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1119  *                                             device
1120  * @dev:        a valid struct device pointer of a sensor device.
1121  * @np:         a pointer to a device tree node.
1122  * @type:       the thermal cooling device type.
1123  * @devdata:    device private data.
1124  * @ops:        standard thermal cooling devices callbacks.
1125  *
1126  * This function will register a cooling device with device tree node reference.
1127  * This interface function adds a new thermal cooling device (fan/processor/...)
1128  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1129  * to all the thermal zone devices registered at the same time.
1130  *
1131  * Return: a pointer to the created struct thermal_cooling_device or an
1132  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1133  */
1134 struct thermal_cooling_device *
1135 devm_thermal_of_cooling_device_register(struct device *dev,
1136                                 struct device_node *np,
1137                                 char *type, void *devdata,
1138                                 const struct thermal_cooling_device_ops *ops)
1139 {
1140         struct thermal_cooling_device **ptr, *tcd;
1141
1142         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1143                            GFP_KERNEL);
1144         if (!ptr)
1145                 return ERR_PTR(-ENOMEM);
1146
1147         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1148         if (IS_ERR(tcd)) {
1149                 devres_free(ptr);
1150                 return tcd;
1151         }
1152
1153         *ptr = tcd;
1154         devres_add(dev, ptr);
1155
1156         return tcd;
1157 }
1158 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1159
1160 static void __unbind(struct thermal_zone_device *tz, int mask,
1161                      struct thermal_cooling_device *cdev)
1162 {
1163         int i;
1164
1165         for (i = 0; i < tz->trips; i++)
1166                 if (mask & (1 << i))
1167                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1168 }
1169
1170 /**
1171  * thermal_cooling_device_unregister - removes a thermal cooling device
1172  * @cdev:       the thermal cooling device to remove.
1173  *
1174  * thermal_cooling_device_unregister() must be called when a registered
1175  * thermal cooling device is no longer needed.
1176  */
1177 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1178 {
1179         int i;
1180         const struct thermal_zone_params *tzp;
1181         struct thermal_zone_device *tz;
1182         struct thermal_cooling_device *pos = NULL;
1183
1184         if (!cdev)
1185                 return;
1186
1187         mutex_lock(&thermal_list_lock);
1188         list_for_each_entry(pos, &thermal_cdev_list, node)
1189                 if (pos == cdev)
1190                         break;
1191         if (pos != cdev) {
1192                 /* thermal cooling device not found */
1193                 mutex_unlock(&thermal_list_lock);
1194                 return;
1195         }
1196         list_del(&cdev->node);
1197
1198         /* Unbind all thermal zones associated with 'this' cdev */
1199         list_for_each_entry(tz, &thermal_tz_list, node) {
1200                 if (tz->ops->unbind) {
1201                         tz->ops->unbind(tz, cdev);
1202                         continue;
1203                 }
1204
1205                 if (!tz->tzp || !tz->tzp->tbp)
1206                         continue;
1207
1208                 tzp = tz->tzp;
1209                 for (i = 0; i < tzp->num_tbps; i++) {
1210                         if (tzp->tbp[i].cdev == cdev) {
1211                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1212                                 tzp->tbp[i].cdev = NULL;
1213                         }
1214                 }
1215         }
1216
1217         mutex_unlock(&thermal_list_lock);
1218
1219         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1220         device_del(&cdev->device);
1221         thermal_cooling_device_destroy_sysfs(cdev);
1222         put_device(&cdev->device);
1223 }
1224 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1225
1226 static void bind_tz(struct thermal_zone_device *tz)
1227 {
1228         int i, ret;
1229         struct thermal_cooling_device *pos = NULL;
1230         const struct thermal_zone_params *tzp = tz->tzp;
1231
1232         if (!tzp && !tz->ops->bind)
1233                 return;
1234
1235         mutex_lock(&thermal_list_lock);
1236
1237         /* If there is ops->bind, try to use ops->bind */
1238         if (tz->ops->bind) {
1239                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1240                         ret = tz->ops->bind(tz, pos);
1241                         if (ret)
1242                                 print_bind_err_msg(tz, pos, ret);
1243                 }
1244                 goto exit;
1245         }
1246
1247         if (!tzp || !tzp->tbp)
1248                 goto exit;
1249
1250         list_for_each_entry(pos, &thermal_cdev_list, node) {
1251                 for (i = 0; i < tzp->num_tbps; i++) {
1252                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1253                                 continue;
1254                         if (tzp->tbp[i].match(tz, pos))
1255                                 continue;
1256                         tzp->tbp[i].cdev = pos;
1257                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1258                                tzp->tbp[i].binding_limits,
1259                                tzp->tbp[i].weight);
1260                 }
1261         }
1262 exit:
1263         mutex_unlock(&thermal_list_lock);
1264 }
1265
1266 /**
1267  * thermal_zone_device_register() - register a new thermal zone device
1268  * @type:       the thermal zone device type
1269  * @trips:      the number of trip points the thermal zone support
1270  * @mask:       a bit string indicating the writeablility of trip points
1271  * @devdata:    private device data
1272  * @ops:        standard thermal zone device callbacks
1273  * @tzp:        thermal zone platform parameters
1274  * @passive_delay: number of milliseconds to wait between polls when
1275  *                 performing passive cooling
1276  * @polling_delay: number of milliseconds to wait between polls when checking
1277  *                 whether trip points have been crossed (0 for interrupt
1278  *                 driven systems)
1279  *
1280  * This interface function adds a new thermal zone device (sensor) to
1281  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1282  * thermal cooling devices registered at the same time.
1283  * thermal_zone_device_unregister() must be called when the device is no
1284  * longer needed. The passive cooling depends on the .get_trend() return value.
1285  *
1286  * Return: a pointer to the created struct thermal_zone_device or an
1287  * in case of error, an ERR_PTR. Caller must check return value with
1288  * IS_ERR*() helpers.
1289  */
1290 struct thermal_zone_device *
1291 thermal_zone_device_register(const char *type, int trips, int mask,
1292                              void *devdata, struct thermal_zone_device_ops *ops,
1293                              struct thermal_zone_params *tzp, int passive_delay,
1294                              int polling_delay)
1295 {
1296         struct thermal_zone_device *tz;
1297         enum thermal_trip_type trip_type;
1298         int trip_temp;
1299         int id;
1300         int result;
1301         int count;
1302         struct thermal_governor *governor;
1303
1304         if (!type || strlen(type) == 0) {
1305                 pr_err("Error: No thermal zone type defined\n");
1306                 return ERR_PTR(-EINVAL);
1307         }
1308
1309         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1310                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1311                        type, THERMAL_NAME_LENGTH);
1312                 return ERR_PTR(-EINVAL);
1313         }
1314
1315         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1316                 pr_err("Error: Incorrect number of thermal trips\n");
1317                 return ERR_PTR(-EINVAL);
1318         }
1319
1320         if (!ops) {
1321                 pr_err("Error: Thermal zone device ops not defined\n");
1322                 return ERR_PTR(-EINVAL);
1323         }
1324
1325         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1326                 return ERR_PTR(-EINVAL);
1327
1328         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1329         if (!tz)
1330                 return ERR_PTR(-ENOMEM);
1331
1332         INIT_LIST_HEAD(&tz->thermal_instances);
1333         ida_init(&tz->ida);
1334         mutex_init(&tz->lock);
1335         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1336         if (id < 0) {
1337                 result = id;
1338                 goto free_tz;
1339         }
1340
1341         tz->id = id;
1342         strlcpy(tz->type, type, sizeof(tz->type));
1343
1344         if (!ops->critical)
1345                 ops->critical = thermal_zone_device_critical;
1346
1347         tz->ops = ops;
1348         tz->tzp = tzp;
1349         tz->device.class = &thermal_class;
1350         tz->devdata = devdata;
1351         tz->trips = trips;
1352         tz->passive_delay = passive_delay;
1353         tz->polling_delay = polling_delay;
1354
1355         /* sys I/F */
1356         /* Add nodes that are always present via .groups */
1357         result = thermal_zone_create_device_groups(tz, mask);
1358         if (result)
1359                 goto remove_id;
1360
1361         /* A new thermal zone needs to be updated anyway. */
1362         atomic_set(&tz->need_update, 1);
1363
1364         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1365         result = device_register(&tz->device);
1366         if (result)
1367                 goto release_device;
1368
1369         for (count = 0; count < trips; count++) {
1370                 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1371                     tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1372                     !trip_temp)
1373                         set_bit(count, &tz->trips_disabled);
1374         }
1375
1376         /* Update 'this' zone's governor information */
1377         mutex_lock(&thermal_governor_lock);
1378
1379         if (tz->tzp)
1380                 governor = __find_governor(tz->tzp->governor_name);
1381         else
1382                 governor = def_governor;
1383
1384         result = thermal_set_governor(tz, governor);
1385         if (result) {
1386                 mutex_unlock(&thermal_governor_lock);
1387                 goto unregister;
1388         }
1389
1390         mutex_unlock(&thermal_governor_lock);
1391
1392         if (!tz->tzp || !tz->tzp->no_hwmon) {
1393                 result = thermal_add_hwmon_sysfs(tz);
1394                 if (result)
1395                         goto unregister;
1396         }
1397
1398         mutex_lock(&thermal_list_lock);
1399         list_add_tail(&tz->node, &thermal_tz_list);
1400         mutex_unlock(&thermal_list_lock);
1401
1402         /* Bind cooling devices for this zone */
1403         bind_tz(tz);
1404
1405         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1406
1407         thermal_zone_device_reset(tz);
1408         /* Update the new thermal zone and mark it as already updated. */
1409         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1410                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1411
1412         thermal_notify_tz_create(tz->id, tz->type);
1413
1414         return tz;
1415
1416 unregister:
1417         device_del(&tz->device);
1418 release_device:
1419         put_device(&tz->device);
1420         tz = NULL;
1421 remove_id:
1422         ida_simple_remove(&thermal_tz_ida, id);
1423 free_tz:
1424         kfree(tz);
1425         return ERR_PTR(result);
1426 }
1427 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1428
1429 /**
1430  * thermal_device_unregister - removes the registered thermal zone device
1431  * @tz: the thermal zone device to remove
1432  */
1433 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1434 {
1435         int i, tz_id;
1436         const struct thermal_zone_params *tzp;
1437         struct thermal_cooling_device *cdev;
1438         struct thermal_zone_device *pos = NULL;
1439
1440         if (!tz)
1441                 return;
1442
1443         tzp = tz->tzp;
1444         tz_id = tz->id;
1445
1446         mutex_lock(&thermal_list_lock);
1447         list_for_each_entry(pos, &thermal_tz_list, node)
1448                 if (pos == tz)
1449                         break;
1450         if (pos != tz) {
1451                 /* thermal zone device not found */
1452                 mutex_unlock(&thermal_list_lock);
1453                 return;
1454         }
1455         list_del(&tz->node);
1456
1457         /* Unbind all cdevs associated with 'this' thermal zone */
1458         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1459                 if (tz->ops->unbind) {
1460                         tz->ops->unbind(tz, cdev);
1461                         continue;
1462                 }
1463
1464                 if (!tzp || !tzp->tbp)
1465                         break;
1466
1467                 for (i = 0; i < tzp->num_tbps; i++) {
1468                         if (tzp->tbp[i].cdev == cdev) {
1469                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1470                                 tzp->tbp[i].cdev = NULL;
1471                         }
1472                 }
1473         }
1474
1475         mutex_unlock(&thermal_list_lock);
1476
1477         cancel_delayed_work_sync(&tz->poll_queue);
1478
1479         thermal_set_governor(tz, NULL);
1480
1481         thermal_remove_hwmon_sysfs(tz);
1482         ida_simple_remove(&thermal_tz_ida, tz->id);
1483         ida_destroy(&tz->ida);
1484         mutex_destroy(&tz->lock);
1485         device_unregister(&tz->device);
1486
1487         thermal_notify_tz_delete(tz_id);
1488 }
1489 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1490
1491 /**
1492  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1493  * @name: thermal zone name to fetch the temperature
1494  *
1495  * When only one zone is found with the passed name, returns a reference to it.
1496  *
1497  * Return: On success returns a reference to an unique thermal zone with
1498  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1499  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1500  */
1501 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1502 {
1503         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1504         unsigned int found = 0;
1505
1506         if (!name)
1507                 goto exit;
1508
1509         mutex_lock(&thermal_list_lock);
1510         list_for_each_entry(pos, &thermal_tz_list, node)
1511                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1512                         found++;
1513                         ref = pos;
1514                 }
1515         mutex_unlock(&thermal_list_lock);
1516
1517         /* nothing has been found, thus an error code for it */
1518         if (found == 0)
1519                 ref = ERR_PTR(-ENODEV);
1520         else if (found > 1)
1521         /* Success only when an unique zone is found */
1522                 ref = ERR_PTR(-EEXIST);
1523
1524 exit:
1525         return ref;
1526 }
1527 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1528
1529 static int thermal_pm_notify(struct notifier_block *nb,
1530                              unsigned long mode, void *_unused)
1531 {
1532         struct thermal_zone_device *tz;
1533
1534         switch (mode) {
1535         case PM_HIBERNATION_PREPARE:
1536         case PM_RESTORE_PREPARE:
1537         case PM_SUSPEND_PREPARE:
1538                 atomic_set(&in_suspend, 1);
1539                 break;
1540         case PM_POST_HIBERNATION:
1541         case PM_POST_RESTORE:
1542         case PM_POST_SUSPEND:
1543                 atomic_set(&in_suspend, 0);
1544                 list_for_each_entry(tz, &thermal_tz_list, node) {
1545                         if (!thermal_zone_device_is_enabled(tz))
1546                                 continue;
1547
1548                         thermal_zone_device_init(tz);
1549                         thermal_zone_device_update(tz,
1550                                                    THERMAL_EVENT_UNSPECIFIED);
1551                 }
1552                 break;
1553         default:
1554                 break;
1555         }
1556         return 0;
1557 }
1558
1559 static struct notifier_block thermal_pm_nb = {
1560         .notifier_call = thermal_pm_notify,
1561 };
1562
1563 static int __init thermal_init(void)
1564 {
1565         int result;
1566
1567         result = thermal_netlink_init();
1568         if (result)
1569                 goto error;
1570
1571         result = thermal_register_governors();
1572         if (result)
1573                 goto error;
1574
1575         result = class_register(&thermal_class);
1576         if (result)
1577                 goto unregister_governors;
1578
1579         result = of_parse_thermal_zones();
1580         if (result)
1581                 goto unregister_class;
1582
1583         result = register_pm_notifier(&thermal_pm_nb);
1584         if (result)
1585                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1586                         result);
1587
1588         return 0;
1589
1590 unregister_class:
1591         class_unregister(&thermal_class);
1592 unregister_governors:
1593         thermal_unregister_governors();
1594 error:
1595         ida_destroy(&thermal_tz_ida);
1596         ida_destroy(&thermal_cdev_ida);
1597         mutex_destroy(&thermal_list_lock);
1598         mutex_destroy(&thermal_governor_lock);
1599         mutex_destroy(&poweroff_lock);
1600         return result;
1601 }
1602 postcore_initcall(thermal_init);